The present invention relates to small scale threshing machines and related apparatus for threshing small lots of seed crops such as those grown at experimental stations and in plots less than an acre in size.
Presently known machinery for small scale threshing makes use of "spike" or "bar" threshing cylinders. Though usually effective, such machinery is complex and is often too expensive to justify expenditure for small "back lot" farmers or experimental growers.
U.S. Pat. No. 2,662,570 to E. F. Hansen discloses a hulling machine that makes use of rotating discs rather than drums for the purpose of hulling castor beans and other nut type seeds. The seeds are fed through the hopper axially between a pair of rubberized discs that rotate relative to one another. The seeds are pinched between the discs and rubbed against the disc surfaces until the hull breaks and falls with the seed meat to a hopper below. This machine is probably serviceable for large, thick hulled seeds such as nuts and beans but could not operate effectively on thin hull seeds such as wheat.
U.S. Pat. No. 1,284,852 to Larisey discloses a peanut shelling machine having a shelling disc rotating about a horizontal axis in a circular housing. Peanuts are fed down radially onto the disc which has blades for shearing the nuts against the housing. An updraft of air is provided by a separate blower to separate the shells from the nuts. The nuts fall to a hopper below the housing. This machine with its shearing action for shelling peanuts would not operate effectively on smaller seed crops such as wheat, barley, oats, etc., which grow on stalks and must be jarred loose before the thin hulls can be effectively removed from the seed. The hulls must be removed by impact and rubbing action that would not be provided by feeding radially into a rotating disc as shown by Larisey.
The problem thus remains of providing a simple yet effective small scale threshing machine for seed crops within the market range of the small lot growers.